Re: [PATCH] Add git-filter-branch

Johannes Schindelin wrote:

This script is derived from Pasky's cg-admin-rewritehist.

In fact, it _is_ the same script, minimally adapted to work without cogito.
It _should_ be able to perform the same tasks, even if only relying on
core-git programs.

All the work is Pasky's, just the adaption is mine.

Signed-off-by: Johannes Schindelin <redacted>
Hopefully-signed-off-by: Petr "cogito master" Baudis [off-list ref]

If you hadn't done that, I'd done it sooner or later. Thanks!

+       -r)
+               unchanged="$(get_parents "$OPTARG") $unchanged"
+               ;;
+       -k)
+               unchanged="$(git-rev-parse "$OPTARG"^{commit}) $unchanged"
+               ;;

These two (-r and -k) together with...

+# seed with identity mappings for the parents where we start off
+for commit in $unchanged; do
+       echo $commit > ../map/$commit
+done

... this and ...

+               if [ -r "../map/$parent" ]; then
+                       for reparent in $(cat "../map/$parent"); do
+                               parentstr="$parentstr -p $reparent"
+                       done
+               else
+                       die "assertion failed: parent $parent for commit $commit not found in rewritten ones"

... this, means that any simple command like 

  git filter-branch -k orgin/master origin/next new-next

of your git.git clone will fail with the "assertion failed". (I haven't
tried your script, yet, but cg-admin-rewritehist fails.)

I propose that you just get rid of the "seed" stance and don't fail if a
commit cannot be mapped - just use it unchanged (don't forget to adjust
the map() function, too). Then you can get rid of -r and use -k to
specify everything you want under "--not" in the rev-list.

-- Hannes